Enhanced Photovoltaic Performance of BiSCl Nanorod Array Solar Cells.

Abstract

BiSCl single-crystalline nanofibers were synthesized by a facile one-pot solvothermal approach for the first time. BiSCl possesses a double chain type structure and grows readily along the c -axis, resulting the fibrous morphology. UV-visible absorption spectrum revealed that BiSCl nanofibers exhibit a strong light absorption in a wavelength range from UV to visible light, corresponding a bandgap of 1.96 eV. UPS spectrum and density functional theory (DFT) calculation revealed that BiSCl is a direct n-type semiconductor with valence band maximum (VBM) and conduction band minimum (CBM) located at 6.04 and 4.08 eV below the vacuum level, respectively. To investigate the photovoltaic performance, the homogeneous thin film of BiSCl-nanorod array was fabricated on a TiO 2 porous film by a modified solvothermal process, where the nanorod array is oriented vertically to the surface of the TiO 2 porous film. BiSCl-based solar cells with an architecture of FTO/TiO 2 /BiSCl/(I 3 - /I - )/Pt gave a power conversion efficiency (PCE) of 1.36% and a relatively larger short-circuit photocurrent density ( J SC ) of 9.87 mA/cm 2 for the first time. The preliminary photovoltaic study result revealed a potential possibility of BiSCl-nanorod array as a light absorber for solar cells which can be fabricated by the low-cost solution process.